75' W100 4X4 issues

[buzter]

Ok I will try an explain this the best I can. I have owned this 75' for quite a few years, I have put in a new engine that probably has 80-90000 miles on it as of now, put in new ring bearings, and a RV cam when I got the engine. The motor as of now has a 2bbl Holley carb and intake. I use the truck for plowing snow..and I tell you what..when it ran good, it could make a mountain of snow. but as of a few years ago, the truck wanted to just fall on its face when It was put into drive, like it had no gas. I have put a refurbed carb on and have put another kit in it as well with no luck after the kit. It ran good when I put the new carb on, but it has been awhile since it was on, hence the kit...I know the bad thing for it is just using it in the winter time but that is what she is used for. So my question is, ideas on why it is falling on its face when I hit the gas..and should I upgrade to a 4bbl intake and carb? Thank you for those who know alot more than I...ask if you have any questions and I will try and answer...been awhile since I worked on her...need to give her some TLC...

[712edf]

I take it that this truck goes undriven for long periods of time. Gasoline stales same as milk or orange juice, only not as fast, gets gummy. Accelerator pump in carb shrinks or dries a tad then becomes ineffective due to poor sealing. Probably not a bad idea to start each winter with fresh fluids and clean plugs. Check vacuum hoses for splits.

These vehicles require almost as much maintance when you don't drive them as when you do.

Bucky

[buzter]

I take it that this truck goes undriven for long periods of time. Gasoline stales same as milk or orange juice, only not as fast, gets gummy. Accelerator pump in carb shrinks or dries a tad then becomes ineffective due to poor sealing. Probably not a bad idea to start each winter with fresh fluids and clean plugs. Check vacuum hoses for splits.

These vehicles require almost as much maintance when you don't drive them as when you do.

Bucky

Yes undrivin for a long period...but it has been this way for quite a few years...but until the last couple years...it has ran great, no problems at all. I do have a heck of a time starting it. I have to pour some gas in the carb each time to get it to start...I can pump it and pump it....but nothing until I dump some gas in the carb then it comes to life after a bit...I have replaced all vaccum hoses on the carb...pvc...

[buzter]

I did add some atf to the gas last year as a local mechanic stated that it would help the accelorater pump in the carb. But to tell you the truth, after rebuilding the carb, it still had this issue of falling when ya hit the pedal to the floor. so I am wondering if I should be looking else where...grounding??? other things to do with distribuiter??? just thinking out loud here....I know I want her to do alot each year with only about 30-50 miles a year...but she had been a good truck...and I let her know it...kind think it helps...haha...

[Ron in Indiana]

I can go along with the gas getting stale from sitting. Dump some Seafoam additive in now and at the end of your season. Have you checked your float level? Are you sure the timing is correct? Changed plugs and wires in awhile? Is the fuel pump working and delivering fuel? Take the fuel line off at the pump and blow air back into the tank to clear the line and pick up. Just trying to cover the bases. On more thing new fuel filter?

[buzter]

I can go along with the gas getting stale from sitting. Dump some Seafoam additive in now and at the end of your season. Have you checked your float level? Are you sure the timing is correct? Changed plugs and wires in awhile? Is the fuel pump working and delivering fuel? Take the fuel line off at the pump and blow air back into the tank to clear the line and pick up. Just trying to cover the bases. On more thing new fuel filter?

Seafoam added...atf added...just today added carb cleaner...float checked last year...good...still had issues...timing was checked a couple years ago...good at that time....plugs not changed in awhile...wires changed within the last couple years...fuel pump...is what I was questioning also....changed filter...

[712edf]

For the record. I have an 83 toyota p/u with a carb. If I do not start it every 24 hrs I have the same issues with dumping gas down it to get it to start. Driven daily it runs fine, let it sit over the weekend and its worse to get going Monday morning than me.

And it doesn't get near as cold here as where you are at.

bucky

[Hawk]

Friend of mine had this issue also but on a different model truck. What they did was pressurize the tank, and well no more issue. Down side is they had to do this each time. So they converted over to an electric fuel pump and now don't have that issue at all.

With the older trucks, there is drain back and metal fuel lines (like the braided ones better). We all know what happens to metal when it sits in water, and all it takes is a pin hole leak to mess up the whole system.

I still have this same issue with my 74, but a few rounds (about 15 to 20 revs) of spinning it over and a few pumps and alive she is. Was thinking of putting in an electric pump just to prime the system before starting it (kind of like what EFI does)

[Bigben]

If you have to add gas each time you start after the truck has sat for a day or two more than likely you have a bad accelerator pump. This can also cause an off idle stumble like you described. The accelerator pump is there to add an extra squirt of gas on quick acceleration so that the main circuit in the carb can catch up with the rush of incoming air into the carb. It also acts as a kind of primer for initial start up by squirting raw fuel into the intake when the accelerator pedal is pumped. Change out the diaphragm in the pump and you should go back to running right.

[buzter]

If you have to add gas each time you start after the truck has sat for a day or two more than likely you have a bad accelerator pump. This can also cause an off idle stumble like you described. The accelerator pump is there to add an extra squirt of gas on quick acceleration so that the main circuit in the carb can catch up with the rush of incoming air into the carb. It also acts as a kind of primer for initial start up by squirting raw fuel into the intake when the accelerator pedal is pumped. Change out the diaphragm in the pump and you should go back to running right.

Bigben...I hear what you are saying...its just hard to believe it is that because I have put in a whole new carb kit...but who knows...I will try and find just a pump and put it in...see what happens, go from there. Thanks for your help

[Bigben]

not sure what kind of holley two barrel you have, but most that I have seen use the same kind of accelerator pump as the four barrel carbs. The diaphragm in these can be changed without pulling the whole carb apart. There will be about a inch and a half plate with four screws and a lever coming out of the center that will be tied into the throttle linkage. Remove the four screws pull out the old diaphragm and spring (there may also be a check ball of some kind I can't remember) and replace the diaphragm with a new one which I believe advanced auto and autozone carry. just look for their holley stuff. If you have an older carb this might not be the case but is worth looking into.

[buzter]

not sure what kind of holley two barrel you have, but most that I have seen use the same kind of accelerator pump as the four barrel carbs. The diaphragm in these can be changed without pulling the whole carb apart. There will be about a inch and a half plate with four screws and a lever coming out of the center that will be tied into the throttle linkage. Remove the four screws pull out the old diaphragm and spring (there may also be a check ball of some kind I can't remember) and replace the diaphragm with a new one which I believe advanced auto and autozone carry. just look for their holley stuff. If you have an older carb this might not be the case but is worth looking into.

I believe it is a 2210 Holley. I will have to get the numbers off the carb and take them in see what they got for me. Thanks again for all your help

[buzter]

Recently also put in new plugs, new wires, cleaned all electrical connections, put grounding straps in for all firewall and fender mounted electronics, cleaned dist, cap, rotor..checked timing looks good, oil chg, fuel additive (carb cleaner upper type).

[Bigben]

just googled the 2210 and it looks as if you will have to pull the top off the carb to get at the accelerator pump. You will need to replace the umbrella shaped rubber on the pump assembly. A quick check you can do to see if the pump is working is with the engine off look into the top of the carb while someone else pumps the gas pedal or work the linkage by hand. If you see a jet of gas squirting into the venturis then your pump is ok if not it needs to be replaced.

[buzter]

ok guys...I put in a new accel pump and made sure I was on the #1 of the tang, bent the linkage a bit to make sure there was fuel going into carb, good squirt...now...same when I put it to the floor...it just dies out then comes back to life...ugg...back at the start of things